How to improve lateral pn-junction electron detectors for microcolumn systems

Design rules for lateral pn-junction detectors have been established and ve rified by numerical simulations and measurements of the detector efficiency for different geometries. The test devices were fabricated by diffusion of phosphorus into boron-doped silicon substrates. The efficiency was measure d by direct electron irradiation in a scanning electron microscope. EBIC im aging was used to obtain the depletion layer width used for calculating the upper limit of the efficiency for the given geometries. All experimental v alues agree well with the theoretical predictions. It is demonstrated that the efficiency of lateral pn-junction detectors can be improved without red uction of the bandwidth. (C) 2001 Elsevier Science B.V. All rights reserved .